The Beautiful World of Algae
Asterionella formosa
Class: Bacillariophyceae (Diatoms)
(Photo source: US National Park Service)

Asterionella formosa

Class: Bacillariophyceae (Diatoms)

(Photo source: US National Park Service)

Pediastrum biwae, one of my personal favorites.
Class: Chlorophyceae (Green Algae).
(Image source: Phytoplankton Key) 

Pediastrum biwae, one of my personal favorites.

Class: Chlorophyceae (Green Algae).

(Image source: Phytoplankton Key